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United States Patent |
6,212,033
|
Sasaki
|
April 3, 2001
|
Slider and method for manufacturing the same
Abstract
The present invention makes it possible to manufacture a slider having two
surfaces at different depths relative to a flying surface.
First etching is performed to form a second surface corresponding to a step
portion using a photoresist mask; thereafter, another photoresist mask is
formed on a region to become a second surface of the slider bar without
removing the former photoresist mask; and second etching is performed
using those photoresist masks to form a third surface corresponding to a
negative pressure generating portion.
Inventors:
|
Sasaki; Yoshitaka (Tokyo, JP)
|
Assignee:
|
TDK Corporation (Tokyo, JP)
|
Appl. No.:
|
272206 |
Filed:
|
March 19, 1999 |
Foreign Application Priority Data
| Mar 31, 1998[JP] | 10-086503 |
Current U.S. Class: |
360/230; 216/47; 360/220; 430/320 |
Intern'l Class: |
G11B 005/60; G03C 005/00; B44C 001/22 |
Field of Search: |
430/320
360/103
216/47
|
References Cited
U.S. Patent Documents
4564585 | Jan., 1986 | Blaske et al.
| |
5019930 | May., 1991 | Takeya | 360/103.
|
5162073 | Nov., 1992 | Aronoff et al. | 156/625.
|
5316617 | May., 1994 | Kawabe et al. | 156/643.
|
5329689 | Jul., 1994 | Azuma et al. | 29/603.
|
5675453 | Oct., 1997 | Matsuzawa et al. | 360/103.
|
5903968 | May., 1999 | Shouji | 29/603.
|
5914202 | Jun., 1999 | Nguyen et al. | 430/5.
|
5949614 | Sep., 1999 | Chhabra | 360/103.
|
6004472 | Dec., 1999 | Dorius et al. | 216/22.
|
6055128 | Apr., 2000 | Dorius et al. | 360/103.
|
Foreign Patent Documents |
B2-5-8488 | Feb., 1993 | JP.
| |
Primary Examiner: Kelly; C. H.
Attorney, Agent or Firm: Oliff & Berridge, PLC
Claims
What is claimed is:
1. A method for manufacturing a slider having a first surface to serve as a
flying surface, a second surface formed in a position at a predetermined
first depth relative to said first surface, a third surface formed in a
position at a predetermined second depth relative to said first surface
greater than said first depth, and a side surface connecting said first
surface and said third surface, the side surface having no step, the
method comprising the steps of:
forming a first etching mask on a region of the material of the slider to
become said first surface;
etching said material to said first depth using said first etching mask to
form said second surface;
forming a second etching mask at least on a region of said material to
become said second surface excluding a region to become said third surface
without removing said first etching mask;
etching said material further using said first and second etching masks by
an amount corresponding to the difference between said second and first
depths to form said third surface; and
removing said first and second etching masks from said material.
2. A method for manufacturing a slider according to claim 1, wherein said
first etching mask is formed by photoresist.
3. A method for manufacturing a slider according to claim 1, wherein said
second etching mask is formed by photoresist.
4. A method for manufacturing a slider according to claim 1, wherein the
step of forming said second surface employs dry etching.
5. A method for manufacturing a slider according to claim 1, wherein the
step of forming said third surface employs dry etching.
6. A method for manufacturing a slider according to claim 1, wherein said
second surface is formed at an air inflow portion.
7. A method for manufacturing a slider according claim 1, wherein said
third surface is formed at a negative pressure generating portion.
8. A method for manufacturing a slider according to claim 1, wherein said
material includes a thin film magnetic head element.
9. A slider having a first surface to serve as a flying surface, a second
surface formed in a position at a predetermined first depth relative to
said first surface, a third surface formed in a position at a
predetermined second depth relative to said first surface greater than
said first depth, and a side surface connecting said first surface and
said third surface, the side surface having no step, the slider produced
by a method comprising the steps of:
forming a first etching mask on a region of the material of the slider to
become said first surface;
etching said material to said first depth using said first etchings mask to
form said second surface;
forming a second etching mask at least on a region of said material to
become said second surface excluding a region to become said third surface
without removing said first etching mask;
etching said material further using said first and second etching masks by
an amount corresponding to the difference between said second and first
depths to form said third surface; and
removing said first and second etching masks from said material.
10. A slider according to claim 9, wherein said second surface is formed at
an air inflow portion.
11. A slider according to claim 9, wherein said third surface is formed at
a negative pressure generating portion.
12. A slider according to claim 9, which includes a thin film magnetic head
element.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a slider used for a flying magnetic head
or the like and a method for manufacturing the same.
2. Description of the Related Art
A flying magnetic head used in a magnetic disc apparatus or the like is
configured by forming a thin film magnetic head element at the rear end of
a slider. In general, a slider includes rail portions whose surfaces act
as flying surfaces (air bearing surfaces) and includes a taper or step
portion in an air inflow portion (in the vicinity of the end at the air
inflow side) such that the rail portions slightly fly above the surface of
a magnetic recording medium such as a magnetic disc by a stream of air
flowing in through the tapered or stepped surface.
In general, a slider having a taper portion at an air inflow portion is
formed into a predetermined configuration through a mechanical process
such as lapping. A slider having a step portion at an air inflow portion
thereof (hereinafter referred to as "a step leading type slider") is
formed into a predetermined configuration through an etching process
utilizing photolithography, for example, as disclosed in Japanese examined
patent publication (KOKOKU) No. H5-8488.
A step leading type slider can be accurately formed even into a complicated
configuration because it is manufactured using photolithography instead of
a mechanical process as described above. This is advantageous in that it
facilitates control over flying characteristics and in that processing
cost can be reduced.
Recently, a need has arisen for a reduction in the flying amount of a
slider for an improved recording density. It is also desired to improve
the stability of the flying of a slider in order to achieve access at a
higher speed. Negative pressure sliders have been put in use to satisfy
such needs. In general, a negative pressure slider is formed with a
negative pressure generating portion having a concave configuration to
generate a negative pressure between two rail portions. Such a negative
pressure slider has a microscopic configuration on a surface thereof
facing a recording medium and, especially, the height of the rail portions
is significantly smaller than those in conventional sliders.
Such a negative pressure slider of the above-described step leading type,
the depths of the step portion and negative pressure generating portion
relative to the flying surfaces are different from each other.
A description will now be made with reference to FIG. 12 through FIG. 21 on
an example of a method for manufacturing a step leading type negative
pressure slider of the related art and on problems with the related-art
methods for manufacturing sliders.
It is assumed here that a slider 211 having a configuration as shown in the
plan view of FIG. 13 is manufactured. The slider 211 includes two rail
portions 212 whose surfaces serve as flying surfaces 212a, a step portion
213 formed at an air inflow portion and a negative pressure generating
portion 214 formed to extend from the central portion to the air outflow
side thereof. For example, the depth of the step portion 213 relative to
the flying surfaces 212a is 1 .mu.m, and the depth of the negative
pressure generating portion 214 relative to the flying surfaces 212a is 3
.mu.m. The slider 211 includes a thin film magnetic head element 215
provided in a position close to the end at the air outflow side of one of
the rail portions 212.
According to the manufacturing method in the related art, the slider bar
including a plurality of thin film magnetic head elements arranged in a
row is first secured to a jig after lapping of the surfaces thereof to
serve as flying surfaces is completed.
The subsequent steps will be described according to the flow chart shown in
FIG. 12. First, as shown in FIGS. 14 and 15, a photoresist mask 231 is
formed using photolithography on regions 222 of the slider bar 210 to
become the rail portions 212 (step S201). FIG. 14 is a plan view showing a
region of the slider bar 210 which is to become one slider, and FIG. 15 is
an enlarged sectional view taken along the line 15--15 in FIG. 14.
Next, for example, ion milling is performed to etch a region 223 to become
the step portion 213 and a region 224 to become the negative pressure
generating portion 214 by, for example, 1 .mu.m using the photoresist mask
231 (step S202).
Next, as shown in FIGS. 16 and 17, the photoresist mask 231 is removed
(step S203). FIG. 16 is a plan view similar to FIG. 14, and FIG. 17 is a
sectional view similar to FIG. 15.
Next, as shown in FIGS. 18 and 19, a new photoresist mask 232 is formed on
the regions 222 to become the rail portions 212 and the region 223 to
become the step portion 213 using photolithography (step S204). FIG. 18 is
a plan view similar to FIG. 14, and FIG. 19 is a sectional view similar to
FIG. 15. Next, for example, ion milling is performed to etch the region
224 to become the negative pressure generating portion 214 by, for
example, 2 .mu.m using the photoresist mask 232 (step S205).
Next, the photoresist mask 232 is removed as shown in FIGS. 20 and 21 (step
S206). The slider 211 is thus formed. FIG. 20 is a plan view similar to
FIG. 14, and FIG. 21 is a sectional view similar to FIG. 15.
According to the method for manufacturing a slider of the related art as
mentioned above, to form the step portion 213 and negative pressure
generating portion 214 which are different in depth from each other
relative to the flying surface 212a, the series of steps of forming
photoresist masks, etching and removing the photoresist mask is repeated
twice. Therefore, when the second photoresist mask 232 is formed, the
photoresist mask 232 must be positioned accurately especially at the
boundaries between the regions 222 to become the rail portions 212 and the
region 224 to become the negative pressure generating portion 214.
In practice, however, when the second photoresist mask 232 is formed, it is
subjected to a positional shift, for example, in the range from 0.3 to 0.5
.mu.m attributable to low positioning accuracy of an exposure mask for
photolithography and the like as shown in FIGS. 18 and 19.
As a result, steps 241 are formed on side surfaces connecting the flying
surfaces 212a and negative pressure generating portion 214 as shown in
FIGS. 20 and 21. When such steps 241 is formed, the flying characteristics
of the slider 211 will be different from design values, which can cause
problems such as a horizontal shift of the slider in use in some cases.
SUMMARY OF THE INVENTION
The present invention has been conceived taking the above-described
problems into consideration, and it is an object of the invention to
provide a method for manufacturing a slider which makes it possible to
accurately manufacture a slider having a first surface to serve as a
flying surface (e.g., the flying surface 212a in FIG. 21), a second
surface formed in a position at a predetermined first depth (e.g., D.sub.1
in FIG. 21) relative to the first surface and a third surface (e.g., the
surface of the negative pressure generating portion 214 in FIG. 21) formed
in a position at a predetermined second depth (e.g., D.sub.2 in FIG. 21)
relative to the first surface greater than the first depth.
It is another object of the invention to provide a slider having a first
surface to serve as a flying surface, a second surface formed in a
position at a predetermined first depth relative to the first surface and
a third surface formed in a position at a predetermined second depth
relative to the first surface greater than the first depth, wherein
designed flying characteristics can be achieved.
A method of manufacturing a slider according to the present invention is a
method for manufacturing a slider having a first surface to serve as a
flying surface, a second surface formed in a position at a predetermined
first depth relative to the first surface and a third surface formed in a
position at a predetermined second depth relative to the first surface
greater than the first depth, which comprises the steps of:
forming a first etching mask on a region of the material of the slider to
become the first surface;
etching the material to a first depth using the first etching mask to form
the second surface;
forming a second etching mask on at least the region of the material to
become the second surface excluding the region to become third surface
without removing the first etching mask;
etching the material further by an amount corresponding to the difference
between the second depth and first depth using the first and second
etching masks to form the third surface; and
removing the first and second etching masks from the material.
According to the method for manufacturing a slider of the present
invention, the first and second etching masks are preferably formed using
photoresist.
According to the method for manufacturing a slider of the present
invention, dry etching is preferably used at the steps of forming the
second and third surfaces.
According to the method for manufacturing a slider of the present
invention, for example, the second and third surfaces are formed at an air
inflow portion and a negative pressure generating portion, respectively.
The material may include a thin film magnetic head element.
A slider according to the present invention is a slider having a first
surface to serve as a flying surface, a second surface formed in a
position at a first depth relative to the first surface and a third
surface formed in a position at a second depth relative to the first
surface greater than the first depth, wherein a side surface connecting
the first and third surfaces is a surface having no step.
In the slider according to the present invention, for example, the second
and third surfaces are formed at an air inflow portion and a negative
pressure generating portion, respectively. The slider according to the
present invention may include a thin film magnetic head element.
Other objects, features and advantages of the present invention will be
sufficiently apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a slider according to an embodiment of the
present invention.
FIG. 2 is a side view showing a state at a step of manufacture of the
slider of the embodiment in which slider bars have been secured to a jig.
FIG. 3 is a flow chart showing a method for manufacturing the slider of the
embodiment.
FIG. 4 is a plan view showing a state at a step of manufacture of the
slider of the embodiment in which a photoresist mask has been formed on
the slider bars.
FIG. 5 is an enlarged sectional view taken along the line 5--5 in FIG. 4.
FIG. 6 is a sectional view showing a state at a step of manufacture of the
slider of the embodiment in which first etching has been carried out.
FIG. 7 is a plan view showing a state in which another photoresist mask has
been formed in the state shown in FIG. 6.
FIG. 8 is an enlarged sectional view taken along the line 8--8 in FIG. 7.
FIG. 9 is a sectional view showing a state at a step of manufacture of the
slider of the embodiment in which second etching has been carried out.
FIG. 10 is a plan view showing a state at a step of manufacture of the
slider of the embodiment in which the photoresist masks have been removed.
FIG. 11 is an enlarged sectional view taken along the line 11--11 in FIG.
10.
FIG. 12 is a flow chart showing an example of a method for manufacturing a
slider according to the related art.
FIG. 13 is a plan view showing an example of a slider according to the
related art.
FIG. 14 is a plan view showing a state at a step of manufacture of the
slider of the related art in which first etching has been carried out.
FIG. 15 is an enlarged sectional view taken along the line 15--15 in FIG.
14.
FIG. 16 is a plan view showing a state at a step of manufacture of the
slider of the related art in which the photoresist mask has been removed.
FIG. 17 is a sectional view showing a state similar to that in FIG. 16.
FIG. 18 is a plan view showing a state at a step of manufacture of the
slider of the related art in which a second photoresist mask has been
formed.
FIG. 19 is a sectional view showing a state similar to that in FIG. 18.
FIG. 20 is a plan view showing a state at a step of manufacture of the
slider of the related art in which second etching has been carried out.
FIG. 21 is a sectional view showing a state similar to that in FIG. 20.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
An embodiment of the present invention will now be described with reference
to the drawings.
First, a description will be made on a configuration of a slider according
to the present invention with reference to the perspective view in FIG. 1.
A slider 11 according to the present embodiment is a step leading type
negative pressure slider which is, for example, used for a flying magnetic
head element. The slider 11 includes two rail portions 12 whose surfaces
are to serve as flying surfaces 1, a step portion 13 formed at an air
inflow portion (in the vicinity of the end at an air inflow side thereof)
and a negative pressure generating portion 14 formed to extend from the
central portion to an air outflow side thereof. For example, the depth
D.sub.1 of the step portion 13 relative to the flying surfaces 1 is 1
.mu.m, and the depth D.sub.2 of the negative pressure generating portion
14 relative to the flying surfaces 1 is 3 .mu.m.
Hereinafter, the flying surfaces are referred to as "first surfaces". The
step portion 13 has a second surface 2 formed in a position at a first
depth D.sub.1 (e.g., 1 .mu.m) relative to the first surfaces 1, and the
negative pressure generating portion 14 has a third surface 3 formed in a
position at a second depth D.sub.2 (e.g., 3 .mu.m) relative to the first
surfaces 1 greater than the first depth.
The slider 11 includes a thin film magnetic head element 15 in a position
in the vicinity of the end at the air outflow side of one of the rail
portions 12.
A method for manufacturing the slider according to the present embodiment
will now be described with reference to FIG. 2 through FIG. 11. According
to the method for manufacturing the slider of the present embodiment, as
shown in FIG. 2, a plurality of slider bars 10 which include a plurality
of thin film magnetic head elements arranged in a row and which have been
lapped on the surfaces thereof to serve as flying surfaces are first
secured to a jig 20 in preparation for steps to be described below. The
slider bars 10 correspond to the material to become a slider in the
context of the present invention. For example, the slider bars 10 are
formed of aluminum oxide and titanium carbide (Al.sub.2 O.sub.3.TiC).
Subsequent steps will now be described according to the flow chart in FIG.
3. As shown in FIGS. 4 and 5, a photoresist mask 31 is first formed using
photolithography on regions 22 of the slider bars 10 to become the rail
portions 12 (step S101). FIG. 4 is a plan view showing a region of the
slider bars 10 to become one slider, and FIG. 5 is an enlarged sectional
view taken along the line 5--5 in FIG. 4. The thickness of the photoresist
mask 31 is preferably on the order of 20 .mu.m. The photoresist mask 31
corresponds to the first etching mask of the present invention.
The step of forming the photoresist mask 31 is specifically carried out as
follows. First, a photoresist layer is formed on the entire surface of the
slider bar 10 including the regions 22 to become the rail portions 12. For
example, one method for forming the photoresist layer is to bond a dry
film made of a photoresist material on using thermal compression. Then,
the photoresist layer is exposed using an exposure mask and is developed
to form the photoresist mask 31 in a predetermined pattern. For example, a
negative type photoresist layer is used, and the exposure mask in this
case has openings in a configuration corresponding to the rail portions
12.
Next, as shown in FIG. 6, a region 23 to become the step portion 13 and a
region 24 to become the negative pressure generating portion 14 are etched
using the photoresist mask 31 to a predetermined depth D.sub.1, e.g., 1
.mu.m to form the second surface 2 on the region 23 to become the step
portion 13 (step S102). FIG. 6 is a sectional view similar to FIG. 5. For
this etching, dry etching such as reactive ion etching or ion milling is
preferably used which allows microscopic features to be formed accurately.
Next, as shown in FIGS. 7 and 8, another photoresist mask 32 is formed
using photolithography at least on the region 23 of the slider bar 10 to
become the step portion 13 (second surface 2) excluding the region 24 to
become the negative pressure generating portion 14 without removing the
photoresist mask 31 (step S103). FIG. 7 is a plan view similar to FIG. 4,
and FIG. 8 is an enlarged sectional view taken along the line 8--8 in FIG.
7. The photoresist mask 32 may extend on a part of the photoresist mask
31. The thickness of the photoresist mask 32 is preferably in the range
from about 10 to 20 .mu.m. The photoresist mask 32 corresponds to the
second etching mask of the present invention. The details of the step of
forming the photoresist mask 32 are similar to the step of forming the
photoresist mask 31.
Next, as shown in FIG. 9, the region 24 to become the negative pressure
generating portion 14 is etched using the photoresist masks 31 and 32 by
an amount corresponding to the difference between the second depth D.sub.2
and first depth D.sub.1, e.g., 2 .mu.m, to form the third surface 3 on the
region 24 to become the negative pressure generating portion 14 (step
S104). FIG. 9 is a sectional view similar to FIG. 8. For this etching, dry
etching such as reactive ion etching or ion milling is preferably used
which allows microscopic features to be formed accurately.
Next, as shown in FIGS. 10 and 11, the slider bar 10 is removed from the
jig 20 and, thereafter, the photoresist masks 31 and 32 are removed (step
S105). FIG. 10 is a plan view similar to FIG. 4, and FIG. 11 is an
enlarged sectional view taken along the line 11--11 in FIG. 10. As a
result, the slider bar 10 is obtained which is a multiplicity of sliders
11 in the configuration shown in FIG. 1 connected together. Thereafter,
the slider bar 10 is cut into the sliders 11 having the configuration
shown in FIG. 1.
As described above, according to the method for manufacturing a slider of
the present embodiment, first etching is performed to form the second
surface 2 using the photoresist mask 31; thereafter, the other photoresist
mask 32 is formed at least on the region 23 of the slider bar 10 to become
the step portion 13 (second surface 2) excluding the region 24 to become
the negative pressure generating portion 14 without removing the
photoresist mask 31; and second etching is performed using the photoresist
masks 31 and 32 to form the third surface 3. Therefore, as shown in FIG.
9, the photoresist mask 31 for the first etching serves as an etching mask
for defining the boundary between the first surface 1 and third surface 3
during the second etching. That is, the same photoresist mask 31 is used
for the first and second etching at the boundary between the first surface
1 and third surface 3. In other words, the second etching is carried out
on a self-alignment basis at the boundary between the first surface 1 and
third surface 3. Therefore, as shown in FIG. 11, the method for
manufacturing a slider according to the present embodiment makes it
possible to prevent the formation of a step on side surfaces 40 which
connect the first surface 1 and third surface 3 to manufacture the slider
11 with high accuracy.
Further, the method for manufacturing a slider according to the present
embodiment allows a reduction in the number of steps because it is not
required to perform the step of removing the photoresist mask 31 prior to
the second etching.
Further, in a slider 11 according to the present embodiment manufactured as
above, the side surfaces 40 connecting the first surface 1 and third
surface 3 are surfaces having no step as shown in FIG. 11. Therefore, a
slider 11 according to the present embodiment can achieve intended flying
characteristics when it is designed as a slider 11 with side surfaces 40
having no step.
The present invention is not limited to the above-described embodiment. For
example, although the embodiment has employed photoresist masks as etching
masks, this is not limiting and metal masks may be used as the etching
masks. However, photoresist masks are preferably used as in the embodiment
because the use of metal masks results in the addition of a
photolithographic step to form the metal masks.
Conditions such as etching time and pressure for the dry etching used in
the present invention may be set in accordance with desired depths.
Referring to the gas used for etching, Ar+CF.sub.4, Ar+BCl.sub.3,
BCl.sub.3 +Cl.sub.2, Ar or the like may be used for reactive ion etching,
and Ar or the like may be used for ion milling.
Although the embodiment has referred to an example of a negative pressure
slider, the present invention may be applied to sliders in which no
negative pressure is generated.
While the embodiment has referred to an example of a slider for a magnetic
head, the present invention may be applied to sliders for other purposes,
e.g., a slider for a head (pick-up) for recording or reproduction of
information on an optical recording or magneto-optical recording basis.
As described above, according to the method for manufacturing a slider of
the present invention, a slider is manufactured which has a first surface
to serve as a flying surface, a second surface formed in a position at a
predetermined first depth relative to the first surface and a third
surface formed in a position at a predetermined second depth relative to
the first surface greater than the first depth by forming a first etching
mask in a region on the material of the slider to become the first
surface, etching the material to the first depth using the first etching
mask to form the second surface, forming a second etching mask at least on
a region of the material to become the second surface excluding a region
to become the third surface without removing the first etching mask;
etching the material further using the first and second etching masks by
an amount corresponding to the difference between the second and first
depths to form the third surface; and removing the first and second
etching masks from the material. As a result, no step is formed on side
surfaces connecting the first and third surfaces during the second etching
to provide an advantage in that a slider can be manufactured with high
accuracy.
The method for manufacturing a slider according to another mode of the
present invention is advantageous in that a slider can be manufactured
with a smaller number of steps because the first etching mask is formed by
photoresist.
The method for manufacturing a slider according to still another mode of
the present invention is advantageous in that a slider can be manufactured
with a smaller number of steps because the second etching mask is formed
by photoresist.
The method for manufacturing a slider according to still another mode of
the present invention is advantageous in that a slider can be manufactured
especially accurately because dry etching is used for the step of forming
the second surface.
The method for manufacturing a slider according to still another mode of
the present invention is advantageous in that a slider can be manufactured
especially accurately because dry etching is used for the step of forming
the third surface.
According to the present invention, there is provided a slider having a
first surface to serve as a flying surface, a second surface formed in a
position at a predetermined first depth relative to the first surface and
a third surface formed in a position at a predetermined second depth
relative to the first surface greater than the first depth, which is
advantageous in that flying characteristics intended by design can be
achieved because side surfaces connecting the first and third surfaces are
surfaces having no step.
It is apparent that various embodiments and modifications of the present
invention are possible based on the above description. Therefore, the
present invention can be embodied in modes other than those in the above
detailed description within the scope of equivalence of the appended
claims.
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